A sampling-based system and method for adaptively optimizing a computer program executing in an execution environment that comprises one or more compiler devices for providing various levels of program optimization. The system comprises a runtime measurements sub-system for monitoring execution of the computer program to be optimized, the monitoring including obtaining raw profile data samples and characterizing the raw profile data; a controller device for receiving the characterized raw profile data from the runtime measurements sub-system and analyzing the data for determining whether a level of program optimization for the executing program is to be performed by a compiler device, the controller generating a compilation plan in accordance with a determined level of optimization; and, a recompilation sub-system for receiving a compilation plan from the controller and invoking a compiler device for performing the level of program optimization of the executing program in accordance with the compilation plan.